This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Diabetes-associated hyperglycemia is the underlying cause of all of the chronic complications arising from a prolonged diabetic condition. The enzyme phosphoenolpyruvate carboxykinase (PEPCK) plays a key role in the elevated blood glucose levels observed during diabetes-associated hyperglycemia. Our studies focus on understanding how PEPCK catalyzes its biological reaction and how it leads to the development of effective inhibitors of this enzyme as potent anti-hyperglycemic agents. Our application's long-term goals are to understand the role that the inherent dynamic properties of protein catalysts play in the process of enzyme mediated catalysis. The results of these studies will have broad reaching implications in the ability to design novel protein-based catalysts, as well as advance our ability to design potent and selective inhibitors of biologically important enzymes in the treatment of disease. By utilizing the enzyme phosphoenolpyruvate carboxykinase our studies will lead directly to the development of selective inhibitors of this enzyme to treat diabetes-associated hyperglycemia. To achieve these goals, we will combine the strengths of x-ray crystallography and NMR to characterize not only the conformational changes that occur during catalysis, but also the time scale in which these motions occur. By correlating these structural and dynamics studies with the ability of the enzyme to carry out catalysis in both the wild-type enzyme and in mutants engineered to upset the dynamic processes, we will achieve a more thorough understanding of the particular roles that these dynamic changes play in the catalytic cycle.